A major police operation is underway on the New South Wales-Queensland border where a baby girl was allegedly murdered with police trying to simulate the incident by studying tidal movements and currents.

Witnesses who have recounted the horror of the deaths of four people on Dreamworld's Thunder River Rapids ride at a coronial inquest face the prospect of being recalled to be questioned further after the theme park's owner belatedly handed over more than 1,000 documents.

Dreamworld's maintenance planner tells an inquest the Thunder River Rapids ride was completely unsafe on the day it malfunctioned killing four people two years ago and that it was "everybody's" job to ensure it was safe.

Subcontractors and the construction union say they fear for the future of businesses and workers on a $1 billion Surfers Paradise development after some construction was suspended and workers laid off.

A spate of inebriated commuters slipping, tripping, and falling at train stations prompts a silly season safety warning from Queensland Rail, which has released CCTV footage of some of its drunk passengers.